Interactions between oxidative stress and attractiveness to mates and individual mate choice in the beetle Tenebrio molitor

Male mating signals are sexual traits that may provide females with information about the physiological quality of the individual. Males of the yellow mealworm beetle, Tenebrio molitor, use pheromones to attract mating partners. The level of pheromone production in males has been identified as a signal of the male condition. We tested whether male sex pheromones also signal the oxidative stress status of their bearers. We used the herbicide paraquat to manipulate the oxidative stress status of individual beetles. We found that healthy males and females preferred healthy mates to those experiencing oxidative stress. If the individual choosing mates was experiencing oxidative stress, females but not males maintained their preference for healthy mating partners. Our study demonstrates a chemical signal indicating the oxidative stress status of a potential partner and reveals that the decisions based on this signal depend upon the condition and gender of the individual making a choice.